1. Field of the Invention
This invention relates to a press used in retaining a prosthetic member in the bone of a patient during surgery, and more particularly to a device and method for exerting force against the prosthetic member, or a pair of prosthetic members, during curing of cement applied to one of the bone or prosthetic member. The press hereof employs an expandable member which enables the surgeon to conduct other tasks once the press is extended until the cement is sufficiently cured.
2. Description of the Prior Art
The use of prosthetic implants in the bone of a patient are well known in the field of orthopedic surgery. In many instances, the bone or cartilage of the patient has been so damaged by injury or disease as to require that the natural joint be replaced by prosthetic implants. For example, in knee arthroplasty, the joint between the femur and the tibia may require that the proximal tibia and the distal femur are cut transversely and the portions of the removed bone are replaced by prosthetic members and the cartilage replaced with a tibia plastic insert. The components and procedures for this surgical technique are illustrated by a booklet, INSALL/BURSTEIN.RTM. Posterior Stabilized II Modular Knee System Surgical Technique and further shown in U.S. Pat. Nos. 4,474,177 and 4,467,801, the contents of which are incorporated herein by reference.
Unfortunately, such surgical procedures are performed with an open incision in the leg or other body member and can be very time consuming. One area which has proven particularly time-consuming is the need to cement the prosthetic members, such as for example, a tibial base or fixation plate and a femoral prosthesis or component, to the bone and allow the cement to sufficiently harden prior to concluding the procedure. The prosthetic members are conventionally of a stainless steel or titanium alloy, and the cement used to secure the prosthetic member to the bone typically requires about twenty minutes to dry or cure. Because the prosthetic member must maintain a good contact with the bone and cement and any voids therebetween reduce the strength of the reconstructed joint, the surgeon typically must manually exert a force of about forty to sixty pounds against the prosthetic member for the entire twenty minutes. In the case of knee replacement surgery, two such twenty minute periods are required--one for the femoral component and one for the tibial base.
As a result, joint replacement operations and knee arthroplasty in particular have been prolonged by the need for the surgeon to personally occupy him or herself with the simple task of holding the prosthetic member in place. During this period, the knee remains open and subject to infection, and the patient is anesthetized. In addition, the surgeon may become fatigued and the contact between the prosthetic member, bone and cement deteriorate if the force applied by the surgeon is substantially lessened. For all these reasons, a need has arisen for a simple, effective tool for limiting the time and effort necessary to ensure a positive contact between the prosthetic member, cement and bone during drying or curing of the cement.